CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority under 35U.S.C. 119.to Japanese Patent Applications
Nos. 2000-336766, 2001-50087 and 2001-307115, filed November 2, 2000, February 26,
2001 and October 3, 2001, respectively, entitled "Fuel Tank Connector". The contents
of these applications are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0002] The present invention relates to a fuel tank connector, in particular a connector
capable of effectively decreasing leakage of evaporative emissions from a fuel tank.
DISCUSSION OF BACKGROUND
[0003] As shown in Figs. 23 and 24, a fuel tank 100 usually has a pipe 101, such as a fuel
feeding pipe and a pipe for guiding gas generating from the fuel, connected thereto.
The connection of the pipe 101 is made by use of a connector 110 fitted to the fuel
tank 100 as shown in Figs. 23 and 24.
[0004] The connector 110, which is shown in Figs. 23 and 24, includes a tubular portion
111 for connection with the pipe 101, a flanged portion 112 projecting laterally from
a peripheral portion of one end of the tubular portion 111 melt-bonded to the tank
100 so as to cover an opening 100a in the tank 100, and a fuel cutoff valve 113 provided
in the flanged portion 112 on a side opposite the tubular portion 111. The tubular
portion 111 and the flanged portion 112 are integrally molded from high-density polyethylene.
[0005] The fuel cutoff valve 113 in the shown connector 110 includes a float chamber forming
box 113b formed in a cylindrical shape, having a valve seat unit 113a with a valve
seat 113a' at the opening of a bore in communication with a bore in the tubular portion
111, having a bottom opened and made of polyacetal; a float 113c having an upper portion
integrally formed with a valve 113e and housed in the box 113b so as to be slidable
therein; and a lid 113d closing the opened bottom of the box 113b and cooperating
with the box to form the float chamber with the float 113c incorporated therein. As
the float 113c rises, the valve 113e makes close contact with the valve seat 113a'
to close the opening.
[0006] In the connector 110, the box 113b of the fuel cutoff valve 113 is configured to
be integrally fitted to the flanged portion 112 so as to have an upper side of the
box 113b embedded in the flanged portion 112 by, e.g., plastic molding wherein the
box is integrally united to the flanged portion with the box being inserted in a mold.
A peripheral portion of the flanged portion 112 with the box 113b is melt-bonded to
a surface of the tank 100 around the opening 100a of the tank 100 with the box 113b
being inserted into the tank 100 through the opening 100a of the tank 100.
[0007] In the connector 110 thus configured, the flanged portion 112 and the tubular portion
111 are made of high-density polyethylene. The evaporative emissions generating from
the fuel in the tank 100 or another member have been predicted to leak out, though
at a regulated value or less, through a portion of the flanged portion 112 provided
between an edge of the opening 100a of the tank and the box 113b of the connector
110 melt-bonded to the tank 100.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide an easy-to-mold connector capable
of effectively decreasing leakage of evaporative emissions from a fuel tank, which
is predicted in the conventional connector.
[0009] In order to attain the object, according to a first aspect of the present invention,
there is provided a fuel tank connector adapted to be fitted to an opening of a fuel
tank to connect the fuel tank and a pipe in communicating fashion, comprising:
a gas barrier member made of a synthetic resin having a gas barrier property, the
gas barrier member including a tubular portion and a flanged portion provided on a
peripheral side of the tubular portion and having a greater side than an opening of
the fuel tank;
wherein the gas barrier member is made of polybutylene terephthalate, polyphenylene
sulfide, a liquid crystal polymer, aliphatic polyketone, aromatic polyamide, a blended
polymer of an ethylene-vinyl alcohol copolymer and high-density polyethylene, a blended
polymer of polyamide and polyethylene, a blended polymer of polyamide and high-density
polyethylene, or polyethylene terephthalate;
the gas barrier member has at least a portion of a surface covered with an outer shell
made of an olefin resin having an adhesive property, polyethylene or high-density
polyethylene; and
the outer shell includes an annular projected portion, which covers a leading end
of the flanged portion and projects toward an outer surface of the fuel tank.
[0010] The fuel tank connector thus constructed can effectively minimize that evaporative
emissions deriving from the fuel in the fuel tank leak from the connector.
[0011] Additionally, the gas barrier member with the outer shell can be melt-bonded to the
fuel tank at the outer shell in reliable and easy fashion.
[0012] With regard to a fuel tank with an outer surface layer made of high-density polyethylene,
the connector can be fitted to the fuel tank through the annular projected portion
of the outer shell with high bonding strength maintained, effectively minimizing the
leakage of the evaporative emissions from the fuel tank by the gas barrier member.
[0013] In order to attain the object, according to a second aspect of the present invention,
the flanged portion has a peripheral portion melt-bonded to a synthetic resin having
a gas barrier property and forming a fuel tank to fit the connector to the fuel tank,
in the first aspect.
[0014] The fuel tank connector thus constructed can further effectively minimize the leakage
of the evaporative emissions from the fuel tank, in addition to the advantages stated
earlier.
[0015] In order to attain the object, according to a third aspect of the present invention,
at least a portion of the outer shell made of an olefin resin having an adhesive property,
and at least a portion of a surface of the gas barrier member uncovered with the outer
shell are covered with an additional outer shell made of high-density polyethylene,
in the first or the second aspect.
[0016] In the fuel tank connector thus constructed, the outer shell, which is made of high-density
polyethylene, can be fitted to the gas barrier member in easier and more reliable
fashion, allowing the connector to be fitted to the fuel tank in more reliable and
easier fashion, in addition to the advantages stated earlier.
[0017] In order to attain the object, according to a fourth aspect of the present invention,
the gas barrier member has the leading end of the flanged portion provided with an
annular projected portion, which projects toward the outer surface of the fuel tank,
in the first, the second or the third aspect.
[0018] In the fuel tank connector thus constructed, design freedom in fitting of the connector
to the fuel tank can increase in such a manner to effectively minimize the leakage
of evaporative emissions from the fuel tank in addition to the advantages stated earlier.
[0019] In order to attain the object, according to a fifth aspect of the present invention,
the gas barrier member has the leading end of the flanged portion provided with an
annular projected portion, which projects toward the outer surface of the fuel tank,
and the connector has the annular projected portion melt-bonded to the outer surface
of the fuel tank, thereby being fitted thereto, in the first aspect.
[0020] With regard to a fuel tank with an outer layer made of high-density polyethylene,
the fuel tank connector thus constructed can be fitted to the fuel tank through the
annular projected portion of the outer shell and the annular projected portion of
the gas barrier member with high bonding strength maintained, effectively minimizing
the leakage of evaporative emissions from the fuel tank by the gas barrier member.
[0021] In order to attain the object, according to a sixth aspect of the present invention,
one of the annular projected portion of the outer shell and the leading end of the
flanged portion of the gas barrier member has a projection formed thereon, and the
outer shell is fitted to the gas barrier member with the projection being inserted
into the other one without the projection, the outer shell being made of polyethylene
or high-density polyethylene, in the first aspect.
[0022] The fuel tank connector thus constructed can ensure to maintain the unity of the
annular projected portion provided on the leading end of the flanged portion of the
gas barrier member and the annular projected portion of the outer shell at high level.
[0023] In order to attain the object, according to a seventh aspect of the present invention,
the gas barrier member has the leading end of the flanged portion provided with an
annular projected portion, which projects toward the outer surface of the fuel tank
and has a projecting length substantially equal to that of the annular projected portion
of the outer shell, and the annular projected portion of the gas barrier member and
the annular projected portion of the outer shell has a cavity formed therebetween
to be opened on a side of the outer surface of the tank, the outer shell made of polyethylene
or high-density polyethylene, in the first aspect.
[0024] In the fuel tank connector thus constructed, when the annular projected portion of
the outer shell is heat-melted, the melted material of polyethylene or high-density
polyethylene forming the annular projected portion can get into the cavity to melt-bond
the annular projected portion to a fuel tank, spreading the melted material of polyethylene
or high-density polyethylene in a wide range.
[0025] When the melt-bonding is carried out to leave some part of the cavity unfilled after
having melt-bonded the annular projected portion of the outer shell to the fuel tank,
the unfilled part can absorb the expansion of the gas barrier member, which could
be caused by fuel or evaporative emissions from the fuel. This arrangement can make
it difficult for a force lowering the melt-bonding strength to be applicable to the
melt-bonded portion between the annular projected portion of the outer shell and the
fuel tank.
[0026] In order to attain the object, according to an eighth aspect of the present invention,
the gas barrier member has the leading end of the flanged portion provided with an
annular projected portion, which projects toward the outer surface of the fuel tank
and has a smaller projecting length substantially than the annular projected portion
of the outer shell, the outer shell being made of polyethylene or high-density polyethylene,
in the first aspect.
[0027] In the fuel tank connector thus constructed, when the annular projected portion of
the outer shell is heat-melted, the melted material of polyethylene or high-density
polyethylene forming the annular projected portion can get into between a projecting
surface of the annular projected portion of the gas barrier member and the outer surface
of the fuel tank to melt-bond the annular projected portion of the outer shell to
the fuel tank, spreading the melted material of polyethylene or high-density polyethylene
in a wide range.
[0028] In order to attain the object, according to a ninth aspect of the present invention,
the gas barrier member, which is covered with the outer shell, has an upper side stepwise
formed so as to have a stepped surface facing the leading end of the flanged portion
of the gas barrier member, the outer shell made of polyethylene or high-density polyethylene,
in the first aspect.
[0029] In the fuel tank connector thus constructed, even if the gas barrier member is swollen
by fuel or evaporative emissions from the fuel, the force caused by the swell can
be received by an opposed surface of the outer shell (made of polyethylene or high-density
polyethylene) in contact with the stepped surface to be dispersed. This arrangement
can make it difficult for a force lowering the melt-bonding strength to be applicable
to the melt-bonded portion between the annular projected portion of the outer shell
and the fuel tank.
[0030] In order to attain the object, according to a tenth aspect of the present invention,
the fuel tank connector is used for connection with a fuel feeding pipe in the first,
the second, the third, the fourth, the fifth, the sixth, the seventh, the eighth or
the ninth aspect.
[0031] The fuel tank connector thus constructed can connect the fuel feeding pipe to the
fuel tank in such a manner to effectively minimize the leakage of evaporative emissions
from fuel, in addition to the advantages stated earlier.
[0032] In order to attain the object, according to an eleventh aspect of the present invention,
the fuel tank connector is used for connection with a vent pipe in the first, the
second, the third, the fourth, the fifth, the sixth, the seventh, the eighth or the
ninth aspect.
[0033] The fuel tank connector thus constructed can connect the vent pipe to the fuel tank
in such a manner to effectively minimize the leakage of evaporative emissions from
fuel, in addition to the advantages stated earlier.
[0034] In order to attain the object, according to a twelfth aspect of the present invention,
the fuel tank connector further comprises a fuel cutoff valve in the first, the second,
the third, the fourth, the fifth, the sixth, the seventh, the eighth or the ninth
aspect.
[0035] The fuel tank connector thus constructed can connect a pipe to the fuel tank through
the fuel cutoff valve, effectively minimizing the leakage of evaporative emissions
from fuel, in addition to the advantages stated earlier.
[0036] As explained, the fuel tank connector according to the present invention, which is
adapted to be fitted to an opening of a fuel tank to connect the fuel tank and a pipe
in communicating fashion, comprises the gas barrier member made of a synthetic resin
and having a gas barrier property, the gas barrier member including the tubular portion
and the flanged portion provided on the peripheral side of the tubular portion and
having a greater side than the opening of the fuel tank; wherein the gas barrier member
is made of polybutylene terephthalate, polyphenylene sulfide, a liquid crystal polymer,
aliphatic polyketone, aromatic polyamide, a blended polymer of an ethylene-vinyl alcohol
copolymer and high-density polyethylene, a blended polymer of polyamide and polyethylene,
a blended polymer of polyamide and high-density polyethylene, or polyethylene terephthalate.
This arrangement can effectively minimize that evaporative emissions deriving from
the fuel in the fuel tank leak from the fuel tank connector.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] A more complete appreciation of the invention and many of the attendant advantages
thereof will be readily obtained as the same becomes better understood by reference
to the following detailed description when considered in connection with the accompanying
drawings, wherein:
Fig. 1 is a vertical cross-sectional view showing the fuel tank connector according
to a first typical embodiment of the present invention showing along with the essential
parts of a fuel tank before fitting the connector to the tank;
Fig. 2 is a plan view showing how the connector is put on the fuel tank before fitting
the connector to the tank;
Fig. 3 is a vertical cross-sectional view showing the connector along with the essential
parts of the fuel tank after fitting the connector to the tank;
Fig. 4 is a vertical cross-sectional view showing the fuel tank connector according
to a second typical embodiment of the present invention along with the essential parts
of a fuel tank before fitting the connector to the tank;
Fig. 5 is a plan view showing how the connector is put on the fuel tank before fitting
the connector to the tank;
Fig. 6 is a vertical cross-sectional view showing the connector along with the tank
after fitting the connector to the tank;
Fig. 7 is a vertical cross-sectional view showing the fuel tank connector according
to a third typical embodiment of the present invention along with a fuel tank before
fitting the connector to the tank;
Fig. 8 is a plan view showing how the connector is put on the tank before fitting
the connector the tank;
Fig. 9 is a vertical cross-sectional view showing the connector along with the tank
after fitting the connector to the tank;
Fig. 10 is a side view of the fuel tank connector according to a fourth typical embodiment
of the present invention;
Fig. 11 is a different side view of the connector shown in Fig. 10;
Fig. 12 is a plan view of the connector according to the fourth embodiment;
Fig. 13 is a vertical cross-sectional view showing the connector according to the
fourth embodiment along with the essential parts of a fuel tank before fitting the
connector to the tank (in the line XIII-XIII in Fig. 12);
Fig. 14 is a vertical cross-sectional view showing the connector along with the essential
parts of the tank after fitting the connector to the tank;
Fig. 15 is a cross-sectional view of the essential parts of the connector according
to the fourth embodiment (before fitting to the tank);
Fig. 16 is a cross-sectional view of the essential parts of the connector (after fitting
to the tank );
Fig. 17 is a cross-sectional view of the essential parts of a modified form of the
connector shown in Figs. 10-16 (before fitting to the tank);
Fig. 18 is a cross-sectional view of the essential parts of the modified form (after
fitting to the tank);
Fig. 19 is a cross-sectional view of the essential parts of another modified form
of the connector shown in Figs. 10-16 (before fitting to the tank);
Fig. 20 is a cross-sectional view of the essential parts of the modified form shown
in Fig. 19 (after fitting to the tank);
Fig. 21 is a cross-sectional view of the essential parts of another modified form
of the connector shown in Figs. 10-16 (before fitting to the tank);
Fig. 22 is a cross-sectional view of the essential parts of the modified form shown
in Fig. 21 (after fitting to the tank);
Fig. 23 is a vertical cross-sectional view showing a conventional fuel tank connector
along with a fuel tank before fitting the connector to the tank; and
Fig. 24 is a vertical cross-sectional view of the conventional connector along with
the tank after fitting the connector to the tank.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] Now, preferred embodiments of the fuel tank connector A according to the present
invention will now be described with reference to the accompanying drawings, wherein
like reference numerals designate corresponding or identical elements throughout the
various drawings.
[0039] Figs. 1-3 show the fuel tank connector A according to a first typical embodiment
of the present invention. Fig. 1 is a vertical cross-sectional view of the fuel tank
connector A according to this embodiment along with the essential parts of a fuel
tank B before the connector has been fitted to the tank, and Fig. 2 is a top plan
view showing how the fuel tank connector A is put on the tank B to be fitted to the
tank.
[0040] Fig. 3 is a vertical cross-sectional view of the fuel tank connector A along with
the essential parts of the fuel tank B after the connector has been fitted to the
tank.
[0041] Figs. 4-6 show the fuel tank connector A according to a second typical embodiment
of the present invention. Fig. 4 is a vertical cross-sectional view of the fuel tank
connector A according to this embodiment along with the essential parts of a fuel
tank B before the connector has been fitted to the tank, and Fig. 5 is a top plan
view showing how the fuel tank connector A is put on the tank B to be fitted to the
tank.
[0042] Fig. 6 is a vertical cross-sectional view of the fuel tank connector A along with
the essential parts of the fuel tank B after the connector has been fitted to the
tank.
[0043] Figs. 7-9 show the fuel tank connector A according to a third typical embodiment
of the present invention. Fig. 7 is a vertical cross-sectional view of the fuel tank
connector A according to this embodiment along with the essential parts of a fuel
tank B before the connector has been fitted to the tank, and Fig. 8 is a top plan
view showing how the fuel tank connector A is put on the tank B to be fitted to the
tank.
[0044] Fig. 9 is a vertical cross-sectional view of the fuel tank connector A along with
the essential parts of the fuel tank B after the connector has been fitted to the
tank.
[0045] Figs. 10-22 show the fuel tank connector A according to a fourth typical embodiment
of the present invention. Figs. 10-12 show the connector A from different views. Fig.
13 is a vertical cross-sectional view of the connector A along with the essential
parts of a fuel tank B before the connector A has been fitted to the tank B, and Fig.
14 is a vertical cross-sectional view of the connector A along with the essential
parts of the tank B after the connector has been fitted to the tank B. Fig. 15 shows
in enlargement a portion of the connector A, which is supposed to be melt-bonded to
the tank B in fitting to the tank B. Fig. 16 shows the portion of the connector, which
has been melt-bonded to the tank B. Figs. 17, 19 and 21 show in enlargement a portion
of the connector to be melt-bonded to the fuel tank B in each of modified forms of
the connector shown in Figs. 10-16 in order to help understanding the modified forms.
Figs. 18, 20 and 22 show in enlargement the portion of the connector, which has been
fitted to the fuel tank B, in each of the modified forms. (Fig. 18 shows how the modified
form of Fig. 17 has been melt-bonded to the fuel tank B, Fig. 20 shows how the modified
form of Fig. 19 has been melt-bonded to the fuel tank B, and Fig. 22 shows how the
modified form of Fig. 21 has been melt-bonded to the fuel tank B.)
[0046] The fuel tank connector A according to each of the typical embodiments is adapted
to be fitted to an inner area Bc of an opening Ba so as to cover the opening Ba formed
in the fuel tank B to connect the fuel tank and a pipe C in communicating fashion.
The connector comprises a gas barrier member 10 made of a synthetic resin having a
gas barrier property, the gas barrier member including a tubular portion 11 and a
flanged portion 12 provided on a peripheral side of the tubular portion 11 and having
a greater side than the opening Ba of the fuel tank B. The gas barrier member 10 is
made of polybutylene terephthalate, polyphenylene sulfide, a liquid crystal polymer,
aliphatic polyketone, aromatic polyamide, a blended polymer of an ethylene-vinyl alcohol
copolymer and high-density polyethylene, a blended polymer of polyamide and polyethylene,
a blended polymer of polyamide and high-density polyethylene, or polyethylene terephthalate.
This arrangement can effectively minimize that evaporative emissions deriving from
the fuel in the fuel tank leak from the connector.
[0047] The fuel tank connector A may be typically configured to have various required properties,
such as fuel oil resistance. The connector is fitted to the inner area Bc of various
types of openings Ba formed in the fuel tank B to connect the fuel tank B and various
types of pipes C, such as a vent pipe and a fuel feeding pipe.
[0048] The fuel tank connector A may be used to connect any type of pipe C to the fuel tank
B in such a state that the connector A is provided with any type of valve, such as,
a fuel cutoff valve 3, or is provided with no valve.
[0049] The gas barrier member 10 forming the fuel tank connector A may be made of polybutylene
terephthalate, polyphenylene sulfide, a liquid crystal polymer, aliphatic polyketone,
aromatic polyamide, a blended polymer of an ethylene-vinyl alcohol copolymer and high-density
polyethylene, a blended polymer of polyamide and polyethylene, a blended polymer of
polyamide and high-density polyethylene, or polyethylene terephthalate, which is suitable
for use as a material of the fuel tank connector A and is a material difficult to
pass gas deriving from any types of fuel stored in the fuel tank B. Any one of the
materials can provide the connector A with a typical gas barrier function.
[0050] Any one of the synthetic materials, which can form the gas barrier member 10 and
has a gas barrier property, is difficult to pass various types of gas deriving from
fuel. The following fuel permeability test, which was carried out to compare some
of the synthetic materials with high-density polyethylene under identical conditions,
shows that any one of the tested synthetic materials were significantly smaller than
the tested high-density polyethylene in fuel permeability amount, and that any one
of the tested synthetic materials had a gas barrier property superior to the tested
high-density polyethylene. "Fuel Permeability Test"
[0051] Respective samples, which were made of the synthetic materials having a gas barrier
property as listed above, and samples, which were made of high-density polyethylene
as stated, were prepared as samples to be measured. Aluminum cups, which had a diameter
of 38 mm, were prepared for each of the samples.
[0052] As test chemicals, the following reagents were prepared:
(1) First reagent: Unleaded regular gasoline (corresponding to JIS K2202 No. 2)
(2) Second reagent: Mixed fuel of 90 vol.% of unleaded regular gasoline (corresponding
to JIS K2202 No. 2) and 10 vol.% of ethanol
[0053] The first reagent of 4.6 g or the second reagent of 4.6 g was put in each of the
aluminum cups. The respective samples to be measured was fixedly put on the respective
aluminum cups so that the respective aluminum cups had their open ends closed with
the respective samples to be measured. The fuel permeability test (the fuel permeability
test prescribed in JIS Z 0208-76),
wherein the fuel permeation amount of a permeable area having 11.341 cm
2 was found by measuring a decrease in weight after lapse of 48 hours at a temperature
of 60°C in a gas phase method, shows the results in Table 1.
Table 1
Synthetic resin sample |
Reagent |
Sample thickness |
Permeation amount |
Sample made of aromatic polyamide (AMODEL (trademark), AT5001; manufactured by Teijin
Amoco Engineering Plastics Co., Ltd. |
First reagent
4.6 g |
0.97 mm |
6 mg |
Sample made of polybutylene terephthalate (DURANEX (trademark) 2002; manufactured
by Polyplastics Co., Ltd.) |
First reagent
4.6 g |
0.98 mm |
10 mg |
Second reagent
4.6 g |
0.98 mm |
8 mg |
Sample made of a blended polymer of an ethylene-vinyl alcohol copolymer and high-density
polyethylene (EVAL (trademark) XEP661; manufactured by Kuraray Co., Ltd.) |
First reagent
4.6 g |
0.93 mm |
100 mg |
Second reagent
4.6 g |
0.93 mm |
94 mg |
Sample made of a blended polymer of polyamide and high-density polyethylene (MC8 (tradename);
manufactured by Toray Industries, Inc.) |
First reagent
4.6 g |
0.96 mm |
0 mg |
Second reagent
4.6 g |
0.96 mm |
3 mg |
Sample made of a blended polymer of polyamide and high-density polyethylene (SP966
(tradename); manufactured by Toray Industries, Inc.) |
First reagent
4.6 g |
0.99 mm |
0 mg |
Second reagent
4.6 g |
0.99 mm |
14 mg |
Sample made of high-density polyethylene (KB145 (tradename); manufactured by Nippon
Polyolefin Co., Ltd. |
First reagent
4.6 g |
0.97 mm |
780 mg |
Second reagent
4.6 g |
0.97 mm |
484 mg |
[0054] The gas barrier member 10 includes the tubular portion 11 and the flanged portion
12 provided on the peripheral side of the tubular portion 11 and having a greater
side than the opening Ba. The gas barrier member may include another part helpful
to the fuel tank connector A, if necessary.
[0055] The connector A comprises a tubular unit 1 and a flange unit 2 to include the tubular
portion 11 and the flanged portion 12 forming the gas barrier member 10. Another part,
such as the fuel cutoff valve 3, may be provided at the tubular unit 1 or the flange
unit 2, forming the connector A.
[0056] The fuel tank B, to which the fuel tank connector A is fitted, may have any structure.
For example, the fuel tank B may be constructed so that its entirety is made of a
synthetic resin, or it has an outer surface around a peripheral edge Bb of the opening
made of a synthetic resin capable of being melt-bonded to the connector A and the
other portion made of a suitable material, such as another synthetic resin or metal.
[0057] The fuel tank connector A thus constructed may have a peripheral portion of the flanged
portion melt-bonded to a synthetic resin Bd having a gas barrier property and forming
the fuel tank B to be fitted to the fuel tank, thereby effectively minimize the leakage
of evaporative emissions from the fuel tank.
[0058] In the fuel tank connector A thus constructed, the gas barrier member 10 may have
at least a portion of a surface, typically at least a portion except the inner side
of the tubular portion 11, covered with an outer shell portion 50a made of an olefin
resin having an adhesive property, allowing the gas barrier member 10 with the outer
shell portion 50a to be melt-bonded to the fuel tank B at the outer shell 50 in reliable
and easy fashion, in addition to the advantage stated earlier.
[0059] In the fuel tank connector A thus constructed, at least a portion of the outer shell
portion 50a, which is made of an olefin resin having an adhesive property to cover
at least a portion of the gas barrier member 10, and at least a portion of a surface
of the gas barrier member 10, which is uncovered with the outer shell portion 50a,
may be covered with an additional outer shell portion 50b made of high-density polyethylene.
Thus, the outer shell portion 50b, which is made of high-density polyethylene, can
be fitted to the gas barrier member 10 in easier and more reliable fashion, allowing
the connector A to be fitted to the fuel tank B in more reliable and easier fashion,
in addition to the advantages stated earlier.
[0060] In the fuel tank connector A thus constructed, the leading end of the flanged portion
12 may be provided with an annular projected portion 12a, which projects toward the
outer surface of the fuel tank B, increasing design freedom in fitting of the connector
to the fuel tank B in such a manner to effectively minimize the leakage of evaporative
emissions from the fuel tank B in addition to the advantages stated earlier.
[0061] The fuel tank connector A thus constructed may be used as a connector for connection
with a fuel feeding pipe to connect the fuel feeding pipe to the fuel tank B in such
a manner to effectively minimize the leakage of evaporative emissions from fuel, in
addition to the advantages stated earlier.
[0062] The fuel tank connector A thus constructed may be used as a connector for connection
with a vent pipe to connect the vent pipe to the fuel tank in such a manner to effectively
minimize the leakage of evaporative emissions from fuel, in addition to the advantages
stated earlier.
[0063] The fuel tank connector A thus constructed may further comprise the fuel cutoff valve
3 to connect a pipe C to the fuel tank B through the fuel cutoff valve, effectively
minimizing the leakage of evaporative emissions from fuel, in addition to the advantages
stated earlier.
(1) Fuel tank connector A according to the first embodiment
[0064] First, the fuel tank connector A according to the first embodiment shown in Figs.
1-3 will be specifically described.
[0065] The fuel tank connector A in the shown embodiment is configured as an instrument
to connect any type of pipe C to the fuel tank B, and is in particular a fuel tank
connector A with the typical fuel cutoff valve 3.
[0066] The fuel tank connector A in the shown embodiment is a connector A adapted to be
fitted to the inner area Bc of the opening Ba so as to cover, from outside, the opening
Ba formed in the fuel tank B to connect the fuel tank B and a pipe C in communicating
fashion. The connector A includes the gas barrier member 10, which comprises the tubular
portion 11 and the flanged portion 12 provided on the peripheral side of the tubular
portion 11 and having a greater side than the opening Ba of the fuel tank B, and which
is made of a synthetic resin having a gas barrier property. The gas barrier member
10 is made of polybutylene terephthalate, polyphenylene sulfide, a liquid crystal
polymer, aliphatic polyketone, aromatic polyamide, a blended polymer of an ethylene-vinyl
alcohol copolymer and high-density polyethylene, a blended polymer of polyamide and
polyethylene, a blended polymer of polyamide and high-density polyethylene, or polyethylene
terephthalate. In the shown embodiment, the gas barrier member 10 has at least a portion
of a surface covered with the outer shell 50, more specifically, at least a portion
of a surface covered with the outer shell portion 50a made of an olefin resin having
an adhesive property. Additionally, at least a portion of the outer shell portion
50a and at least a portion of the gas barrier member uncovered with the outer shell
portion 50a are covered with the outer shell portion 50b made of high-density polyethylene.
The connector A can be melt-bonded to the fuel tank B at the outer shell 50 to effectively
minimize that evaporative emissions deriving from the fuel in the fuel tank B leak
from the connector.
[0067] The fuel tank connector A in the shown embodiment is used as an instrument to connect
any type of pipe C to the fuel tank B. In the shown embodiment, the connector A is
provided with the typical fuel cutoff valve 3 and is fitted to an upper side of the
fuel tank B as a typical example. The connector serves to feed, e.g., evaporative
emissions deriving from fuel to a charcoal canister or another device and to prevent
the fuel from flowing out when the fuel level in the fuel tank B changes.
[0068] In the fuel tank B, to which the connector A in the shown embodiment is fitted, at
least a portion of the tank with the outer shell 50 of the connector A melt-bonded
thereto, i.e., an outer surface of the tank around the peripheral edge Bb of the opening
in the fuel tank B is made of a synthetic resin capable of being melt-bonded to the
outer shell 50 and includes a gas barrier layer, i.e., a layer difficult to pass evaporative
emissions from the fuel.
[0069] The fuel tank B typically includes an outer surface layer Be made of a synthetic
resin convenient for melt-bonding with the connector A, such as high-density polyethylene,
and the gas barrier layer Bd made of a synthetic resin layer to make it difficult
to pass evaporative emissions from the fuel. In the shown embodiment, the outer surface
layer Be has a portion removed to provide a circumferential recessed portion Bf around
the peripheral edge Bb of the opening so that the gas barrier layer Bd having a gas
barrier property is exposed at the circumferential recessed portion.
[0070] The connector A in the shown embodiment includes the tubular unit 1 with a bore 1e,
the flange unit 2 provided on a peripheral side of the tubular unit 1 and having a
greater outer diameter than the opening Ba, and the fuel cutoff valve 3. With a cylindrical
portion 23 forming a cylindrical body 20 of the fuel cutoff valve 3 inserted into
the fuel tank B through the opening Ba of the fuel tank B, the flange unit 2 is melt-bonded
to a surface of the fuel tank, which is made of a synthetic resin at least around
the peripheral edge Bb of the opening. Thus, the connector A is used for connecting
the fuel tank B and a pipe C in communicating fashion through the bore 1e.
[0071] The opening Ba in the shown embodiment is formed in a circular shape, and the flange
unit 2 is formed as circular plate, which has a greater diameter than the opening
Ba.
[0072] The connector A in the shown embodiment specifically includes the tubular unit 1,
which comprises a vertical tubular portion 1a projecting upwardly and a horizontal
tubular portion 1b connected to an upper end of the vertical tubular portion 1a so
as to be bent from the vertical tubular potion 1a at right angles, and the flange
unit 2 which comprises the circular plate projecting laterally from a periphery of
a lower end of the vertical tubular portion 1a in the tubular unit 1. The flange unit
additionally includes the fuel cutoff valve 3, which comprises a disk-shaped portion
21 jutted downwardly from the flange unit 2, i.e., in a direction away from the tubular
unit 1, the cylindrical portion 23 extending downwardly from a peripheral edge of
the disk-shaped portion 21, a lid 24 with an engagement projection 23b engaged with
an engagement slot 24c formed in a lower edge of the cylindrical portion 23, a valve
seat unit 30 provided in a recessed portion 22 in the disk-shaped portion 21 in communication
with the bore 1e in the tubular unit 1, and a float 40 housed in a float chamber so
as to be vertically movable in response to a change in the liquid level of the liquid
entering the float chamber, the float chamber comprising the disk-shaped portion 21
having the valve seat unit 30 with a valve seat 30b, the cylindrical portion 23 and
the lid 24. A valve body 40a, which is provided on an upper end of the float 40, is
configured to get in close contact with the valve seat 30b in the valve seat unit
30 to close the bore 1e of the tubular unit 1 when the float 40 moves toward the valve
seat 30b as the liquid level changes.
[0073] The gas barrier member 10 provided on the connector A is made of a synthetic resin
having a gas barrier property to avoid the transmission of gas, typically evaporative
emissions deriving from the fuel in the tank B, as much as possible. Examples of the
synthetic resin are polybutylene terephthalate, polyphenylene sulfide, a liquid crystal
polymer, aliphatic polyketone, aromatic polyamide, a blended polymer of an ethylene-vinyl
alcohol copolymer and high-density polyethylene, a blended polymer of polyamide and
polyethylene, a blended polymer of polyamide and high-density polyethylene, and polyethylene
terephthalate. In the shown embodiment, the gas barrier member includes the tubular
portion 11 with a passage 11e forming the bore 1e and the flanged portion 12 projecting
laterally from the peripheral edge of the one end of the tubular portion 11.
[0074] The tubular portion 11 has an elbow-like shape, wherein a vertical tubular portion
11b is connected to a horizontal tubular portion 11a at right angles. The flanged
portion 12 is integrally fitted to the vertical tubular portion 11b so as to project
laterally from the peripheral portion of the lower end of the vertical tubular portion.
[0075] The flanged portion 12, which is provided on the peripheral portion of the vertical
tubular portion 11b, is configured to have a greater side than the opening Ba in the
fuel tank B, i.e., the flanged portion 12 on the tubular portion 11 is configured
to laterally extend from the peripheral portion of the tubular portion 11 toward the
peripheral edge Bb of the opening in the fuel tank B. Specifically, the flanged portion
12 is formed as a circular plate, which has a greater diameter than the opening Ba
in a circular shape.
[0076] The annular projected portion 12a extends in a bent form downwardly from a side of
the flanged portion 12 facing the outer surface of the fuel tank B, i.e., a peripheral
edge of the flanged portion 12 remote from the projected tubular portion 11, or toward
the fuel tank B.
[0077] The fuel cutoff valve 3 is integrally fitted to a lower side of the gas barrier member
thus constructed, which is located on a side remote from the projected tubular portion
11.
[0078] The fuel cutoff valve 3 includes the cylindrical body 20 having an upper side integrally
provided with the disk-shaped portion 21 and integrally fitted to the gas barrier
member 10, the valve seat unit 30 integrally fitted to the disk-shaped portion 21
in the cylindrical body 20, the lid 24 fitted to a lower end of the cylindrical portion
to close the bottom opening of the cylindrical body 20, and the float 40 housed in
the float chamber provided in the cylindrical body 20 closed by the lid 24 for opening
and closing the valve seat 30b in the valve seat unit 30, following a change in the
fuel liquid level.
[0079] The cylindrical body 20 forming the fuel cutoff valve 3 includes the disk-shaped
portion 21 and the cylindrical portion 23 integrally projected from the disk-shaped
portion 21, and the cylindrical body is made of any type of synthetic resin, typically,
a synthetic resin having a gas barrier property, such as polyacetal.
[0080] The disk-shaped portion 21 forming the cylindrical body 20 has a wall with a cavity
21a therein, which communicates with outside to accept the entry of a resin in molding.
The disk-shaped portion also has a peripheral edge integrally provided with the cylindrical
portion 23, which extends downwardly. Additionally, the disk-shaped portion 21 has
a substantially central portion formed with the recessed portion 22, which communicates
with the passage 11e in the tubular portion 11 and forms an opening 11c of the tubular
portion 11.
[0081] The recessed portion 22 formed in the disk-shaped portion 21 communicates with the
passage 11e in the tubular portion 11 and has a larger diameter than the passage 11e.
In the shown embodiment, the recessed portion comprises a large diameter of stepped
hole 22a formed in a lower end of the disk-shaped portion 21 so as to be upwardly
recessed, a conical hole 22b extending from an upper end of the stepped hole 22a toward
the tubular portion 11, and another stepped hole 22c extending from the conical hole
22b to the tubular portion 11.
[0082] The cylindrical portion 23 is formed as a cylindrical and open-bottomed body, which
projects from the disk-shaped portion 21 as one unit. The cylindrical portion has
an outer portion on a leading side as a lower edge formed with the engagement projection
23b for engagement with the lid 24 and a peripheral wall formed with a plurality of
holes 23a. The cylindrical portion 23 has an inner wall formed with a plurality of
guide ribs 23c, which extend from a lower portion toward the disk-shaped portion 21.
[0083] The holes 23a formed in the cylindrical portion 23 serve to smoothly move gas or
another fluid between the inner space in the fuel tank B and the inner space in the
cylindrical portion 23, which houses the float 40 therein and is closed by the lid
24.
[0084] The cylindrical body 20 thus constructed and the gas barrier member 10 are integrally
fitted by, e.g., inserting the cylindrical body 20 in a mold, injecting a synthetic
resin for molding the gas barrier member 10 into the mold by injection or anther way,
and molding the gas barrier member 10 so as to cover a peripheral portion of the disk-shaped
portion 21 in the cylindrical body 20 and a side of the disk-shaped portion 21 remote
from the projected cylindrical portion 23 with the synthetic resin as well as filling
the synthetic resin into the cavity 21a in the cylindrical body 21.
[0085] In the shown embodiment, the gas barrier member 10 is integrally fitted to the cylindrical
body 20 so that the gas barrier member includes the flanged portion 12 covering the
side of the disk-shaped portion remote from the projected cylindrical portion 23 and
laterally projecting from the side, a covering portion 12b projecting from a lower
side of the flanged portion 12 so as to cover the peripheral portion of the disk-shaped
portion 21, the tubular portion 11 having the passage 11e in communication with the
stepped hole 22c in the disk-shaped portion 21 and upwardly projecting from the upper
side of the flanged portion 12, and the annular projected portion 12 downwardly extending
from the leading end of the disk-shaped portion 12 in a bent form.
[0086] In the shown embodiment, the outer surface of the gas barrier member 10, which is
integrally fitted to the cylindrical body, is covered by the outer shell 50, which
extends on an outer surface of the covering portion 12b and a portion of the outer
surface of the gas barrier member 10 from the outer surface of the covering portion
to an open end 11d through the leading edge of the annular projected portion 12a.
[0087] The outer shell 50 to be provided on the gas barrier member 10 can be formed on the
surface of the gas barrier member 10 by plastics molding wherein the cylindrical body
20 with the gas barrier member 10 integrally fitted thereto is inserted into a mold,
for instance.
[0088] The outer shell 50, which is provided so as to cover the surface of the gas barrier
member 10, can be molded integrally with the gas barrier member 10. The outer shell
is made of a synthetic resin capable of being melt-bonded to the fuel tank B. In the
shown embodiment, the outer shell has a layered structure, wherein the outer shell
integrally includes the outer shell portion 50a, which is made of an olefin resin
having an adhesive property, and which covers the outer surface of the covering portion
12b and a portion of the outer surface of the gas barrier member 10 from the outer
surface of the covering portion to a middle portion of the vertical tubular portion
11b through the leading edge of the annular projected portion 12a, and the outer shell
portion 50b, which is made of high-density polyethylene, and which covers a peripheral
surface of the outer shell portion 50a continuous to a surface of the outer shell
portion 50a facing the fuel tank B, and a surface from the peripheral surface to the
open end 11d of the tubular portion 11, i.e., the surfaces formed by the outer shell
portion 50a made of an olefin resin having an adhesive property and the gas barrier
member 10.
[0089] In other words, in the shown embodiment, the flange unit 2 and the tubular unit 1
of the connector A are provided so that the outer shell 50 is integrally fitted to
the flanged portion 12 and the tubular portion 11 in the gas barrier member 10. The
flange portion 2 has the leading edge formed with an annular projection 2a, which
comprises the annular projected portion 12a and the outer shell 50 covering the annular
projected portion 12a.
[0090] The valve seat unit 30, which is arranged in the recessed portion 22 of the disk-shaped
portion 21 in the cylindrical body 20 to provide the fuel cutoff valve 3 with the
valve seat 30b, is made of a synthetic resin adapted to melt-bonding to the disk-shaped
portion 21 and cooperating with the disk-shaped portion 21 to provide the connector
A with a gas barrier function, i.e., any type of synthetic resin having a gas barrier
property to effectively avoid the transmission of evaporative emissions deriving from
the fuel, such as polyacetal. The valve seat unit has such a form that the valve seat
30b, which receives the valve body 40a of the float 40 to be closed, is provided on
the edge of an aperture 30a vertically passing through the valve seat 30b and is incorporated
into the recessed portion 22.
[0091] Specifically, the valve seat body 30 has the aperture 30a formed in a substantially
central portion to vertically pass therethrough and communicate with the bore 1e or
the passage 11e. The aperture 30a has a central portion formed with a restricted orifice
30a' and a portion below the restricted orifice 30a' formed with the conical valve
seat 30b gradually expanding toward a lower edge of the aperture 30a. The valve seat
body 30 has an upper end formed with an annular groove 30c to surround the aperture
30a. The annular groove 30c provides a cylindrical part 30d to an upper central portion
of the valve seat body 30. The outer wall of the annular groove 30c forming the cylindrical
part 30d comprises an upper disk part 30e and a lower disk part 30f provided below
the upper disk part 30e and having a greater diameter than the upper disk part 30e.
The valve seat body 30 is melt-bonded and integrally fitted to the disk-shaped portion
21 so that the upper disk part 30e has an upper end pressed against the conical hole
22b with an annular seal 31 fitted to the outer peripheral surface of the upper disk
part 30e, and so that the lower disk part 30f is housed in the larger diameter of
stepped hole 22a at the lowest position so as to put the upper end of the lower disk
part 30f into close contact with the upper end of the larger diameter of stepped hole
22a.
[0092] The float 40, which is incorporated in the cylindrical body 20 thus constructed,
is made of, e.g., polyacetal and is guided by the guide ribs 23c in the cylindrical
portion 23 to be vertically movable in smooth fashion, following a change in the fuel
liquid level. The float has the upper end formed with the valve body 40a to get in
close contact with the valve seat 30b to close the aperture 30a in the valve seat
body 30 when the float is moved toward the valve seat 30b by a change in the fuel
liquid level. The float has a substantially central portion on a lower side formed
with a recess 40b upwardly extending, and the recess 40b includes an annular recess
40b' further upwardly extending and a circular base 40c. The float includes a hole
40d formed therein to communicate between the recess 40b and the upper end of the
float.
[0093] The lid 24, which keeps the float 40 forming the fuel cutoff valve 3 incorporated
in the cylindrical portion 23, includes a cylindrical peripheral wall 24b, which upwardly
extends from a peripheral edge of a bottom wall 24a in a circular plate shape. The
cylindrical peripheral wall 24b receives the cylindrical portion 23 so as to get the
leading edge of the cylindrical portion 23 in contact with the bottom wall 24a, and
the cylindrical portion 23 has the engagement projection 23b thereon engaged with
an edge of the engagement slot 24c in the cylindrical peripheral wall 24b to assemble
the lid to the cylindrical portion 23. The lid 24 has a substantially central portion
on an inner side formed with a circular base 24d, and a helical compression spring
41 is disposed on the circular base 24d of the lid and the circular base 24c of the
float 40 to assemble the float 40 to the cylindrical portion 23 so that the float
is easily movable in floating fashion in the cylindrical portion, following a change
in the fuel liquid level.
[0094] The lid 24, which assembles the float 40 into the cylindrical portion 23, has the
bottom wall 24a formed with a plurality of apertures 24e, which vertically pass through
the bottom wall 24a, allowing fuel or gas to easily flow into and out of the cylindrical
portion 23.
[0095] When the float 40 does not receive the buoyancy from the fuel liquid, the helical
compression spring 41 balances with the weight of the float 40 and elastically supports
the float 40 so as to maintain the valve body 40a in a position away from the valve
seat 30b. When the float 40 receives the buoyancy from the fuel liquid, the helical
compression spring allows the float 40 to float up easily and move upwardly by the
buoyancy. In the latter case, the helical compression spring causes the float 40 to
press its valve body 40a into contact with the valve seat 30b against the buoyancy,
e.g., if the vehicle with the fuel tank turns over.
[0096] In the connector A, which includes the tubular unit 1 and the flange unit 2 comprising
the outer shell 50 and the gas barrier member 10 thus constructed and also includes
the fuel cutoff valve 3, the valve seat unit 30 is integrally melt-bonded and fitted
to the disk-shaped portion 21 forming the fuel cutoff valve 3. The cylindrical portion
23 has the float 40 housed therein and the lid 24 fitted to the open bottom thereof
with the helical compression spring 41 interposed between the housed float 40 and
the lid.
[0097] In the shown embodiment, the connector A thus constructed has the side of the cylindrical
portion 23 inserted into the fuel tank B through the opening Ba formed in the upper
side of the fuel tank B. The annular projected portion 12a of the gas barrier member
10 in the connector A is melt-bonded to the synthetic resin Bd having a gas barrier
property exposed in the circumferential recessed portion Bf formed in the fuel tank
B. The annular projected portion 2a is housed in the circumferential recessed portion
Bf so as to be melt-bonded to the fuel tank B. The annular projected portion 12a is
melt-bonded to the synthetic resin Bd having a gas barrier property, and the outer
shell 50 has the annular projected portion 2a melt-bonded to the fuel tank B.
[0098] By fitting the connector A to the inner area Bc of the opening formed in the fuel
tank B as explained, the gas barrier member 10 can effectively decrease the leakage
of evaporative emissions deriving from the fuel from the fuel tank B.
[0099] The connector A can be easily and reliably fitted to the fuel tank B since fitting
the connector A to the fuel tank B is carried out by melt-bonding the connector A
to the fuel tank B.
[0100] The leakage of the gas from the fuel tank B can be further effectively decreased
since the connector A is fitted to the fuel tank B by melt-bonding the gas barrier
member 10 in the connector A to the synthetic resin Bd having a gas barrier property
in the fuel tank B.
[0101] The connector A, which has been fitted to the fuel tank B as explained, may be used
for connection with a suitable pipe C.
[0102] In order to that the connector A can easily and reliably maintain the connection
with the pipe C, the tubular unit 1 of the connector has an outer peripheral surface
of the horizontal tubular portion 1b formed with a plurality of ridges, which comprise
conical guides 1c having a diameter gradually reduced toward the open end of the tubular
unit and vertical stepped surfaces 1d extending from respective edges of the conical
guides remote from the open end to the outer peripheral surface of the horizontal
tubular portion 1b, in the shown embodiment.
(2) Fuel tank connector A according to the second embodiment
[0103] Next, the fuel tank connector A according to the second embodiment shown in Figs.
4-6 will be specifically described.
[0104] The fuel tank connector A in the shown embodiment is configured as an instrument
to connect any type of pipe C to the fuel tank B, and is in particular a fuel tank
connector A with the typical fuel cutoff valve 3, which is fitted to the upper side
of the fuel tank B.
[0105] The fuel tank connector A in the shown embodiment is a connector A adapted to be
fitted to the inner area Bc of the opening Ba so as to cover, from outside, the opening
Ba formed in the fuel tank B to connect the fuel tank B and a pipe C in communicating
fashion. The connector A includes the gas barrier member 10, which comprises the tubular
portion 11 and the flanged portion 12 provided on the peripheral side of the tubular
portion 11 and having a greater side than the opening Ba of the fuel tank B, and which
is made of a synthetic resin having a gas barrier property. The gas barrier member
10 is made of polybutylene terephthalate, polyphenylene sulfide, a liquid crystal
polymer, aliphatic polyketone, aromatic polyamide, a blended polymer of an ethylene-vinyl
alcohol copolymer and high-density polyethylene, a blended polymer of polyamide and
polyethylene, a blended polymer of polyamide and high-density polyethylene, or polyethylene
terephthalate. In the shown embodiment, the gas barrier member 10 has at least a portion
of a surface covered with the outer shell 50, more specifically, at least a portion
of a surface covered with an outer shell portion 50a made of an olefin resin having
an adhesive property. The connector A can be melt-bonded to the fuel tank B at the
outer shell 50 to effectively minimize that evaporative emissions deriving from the
fuel in the fuel tank B leak from the connector.
[0106] The fuel tank connector A according to the second embodiment as the same structure
or substantially the same structure as the fuel tank connector A according to the
first embodiment except that the outer shell 50 is made of a single layer of adhesive
olefin resin and is provided on the gas barrier member 10 forming the fuel tank connector
A according to the second embodiment. The connector according to the second embodiment
can be fitted to the fuel tank A by the same method as the connector according to
the first embodiment.
[0107] Parts identical to or substantially identical to the parts of the fuel tank connector
A according to the first embodiment are designated by like reference numerals, and
explanation on these parts will be omitted.
[0108] In the fuel tank connector A according to the second embodiment, the outer shell
50, which is supposed to be the gas barrier member 10, may be provided on the gas
barrier member 10 by, e.g., plastics molding, wherein the cylindrical body 20 with
the gas barrier member 10 integrally provided thereto is inserted into a mold as in
the preparation for the fuel tank connector A according to the first embodiment.
[0109] The outer shell 50, which is provided so as to cover the surface of the gas barrier
member 10, can be molded integrally with the gas barrier member 10. The outer shell
is made of a synthetic resin capable of being melt-bonded to the fuel tank B. In the
shown embodiment, the outer shell includes the outer shell portion 50a, which is made
of an olefin resin having an adhesive property, and which covers the outer surface
of the covering portion 12b and a portion of the outer surface of the gas barrier
member 10 from the outer surface of the covering portion to the open end 11d of the
tubular portion 11 through the leading edge of the annular projected portion 12a so
as to be integral with the gas barrier member 10.
[0110] In the shown embodiment, the connector A thus constructed has the side of the cylindrical
portion 23 inserted into the fuel tank B through the opening Ba formed in the upper
side of the fuel tank B. The annular projected portion 12a of the bas barrier member
10 in the connector A is melt-bonded to the synthetic resin Bd having a gas barrier
property exposed in the circumferential recessed portion Bf formed in the fuel tank
B. The annular projected portion 2a is housed in the circumferential recessed portion
Bf and is melt-bonded to the fuel tank B. The annular projected portion 12a is melt-bonded
to the synthetic resin Bd having a gas barrier property, and the outer shell 50 has
the annular projected portion 2a melt-bonded to the fuel tank B.
[0111] By fitting the connector A to the inner area Bc of the opening formed in the fuel
tank B as explained, the gas barrier member 10 can effectively decrease the leakage
of evaporative emissions deriving from the fuel from the fuel tank B.
[0112] The connector A can be easily and reliably fitted to the fuel tank B since fitting
the connector A to the fuel tank B is carried out by melt-bonding the connector A
to the fuel tank B.
[0113] The leakage of the gas from the fuel tank B can be further effectively decreased
since the connector A is fitted to the fuel tank B by melt-bonding the gas barrier
member 10 in the connector A to the synthetic resin Bd having a gas barrier property
in the fuel tank B.
(3) Fuel tank connector A according to the third embodiment
[0114] First, the fuel tank connector A according to the third embodiment shown in Figs.
7-9 will be specifically described.
[0115] The fuel tank connector A in the shown embodiment is configured as an instrument
to connect any type of pipe C to a fuel tank B, and is in particular a fuel tank connector
A with the typical fuel cutoff valve 3.
[0116] The fuel tank connector A in the shown embodiment is a connector A adapted to be
fitted to the inner area Bc of the opening Ba so as to cover, from outside, the opening
Ba formed in the fuel tank B to connect the fuel tank B and a pipe C in communicating
fashion. The connector A includes the gas barrier member 10, which comprises the tubular
portion 11 and the flanged portion 12 provided on a peripheral side of the tubular
portion 11 and having a greater side than the opening Ba of the fuel tank B, and which
is made of a synthetic resin having a gas barrier property. The gas barrier member
10 is made of polybutylene terephthalate, polyphenylene sulfide, a liquid crystal
polymer, aliphatic polyketone, aromatic polyamide, a blended polymer of an ethylene-vinyl
alcohol copolymer and high-density polyethylene, a blended polymer of polyamide and
polyethylene, a blended polymer of polyamide and high-density polyethylene, or polyethylene
terephthalate. In the shown embodiment, the gas barrier member 10 has at least a portion
of a surface covered with the outer shell 50, more specifically, s side facing the
fuel tank B integrally fitted with an outer shell portion 50c made of a modified polyolefin
resin having an adhesive property. The connector A can be melt-bonded to the fuel
tank B at the outer shell portion 50c to effectively minimize that evaporative emissions
deriving from the fuel in the fuel tank B leak from the connector.
[0117] The fuel tank connector A in the shown embodiment is used as an instrument to connect
any type of pipe C to the fuel tank B. In the shown embodiment, the connector A is
provided with the typical fuel cutoff valve 3 and is fitted to the upper side of the
fuel tank B as a typical example. The connector serves to feed, e.g., evaporative
emissions deriving from fuel to a charcoal canister or another device and to prevent
the fuel from flowing out when the fuel level in the fuel tank B changes.
[0118] In the fuel tank B, to which the connector A in the shown embodiment is fitted, at
least a portion of the tank with the connector A melt-bonded thereto, i.e., an outer
surface of the tank around the peripheral edge Bb of the opening in the fuel tank
B is made of a synthetic resin capable of being melt-bonded to an outer shell 50 and
includes a gas barrier layer, i.e., a layer difficult to pass evaporative emissions
from the fuel.
[0119] The fuel tank B typically includes the outer surface layer Be made of a synthetic
resin convenient for melt-bonding with the connector A, such as polyethylene and high-density
polyethylene, and the gas barrier layer Bd made of a synthetic resin layer to make
it difficult to pass evaporative emissions from the fuel. In the shown embodiment,
the outer surface layer Be has a portion removed to provide the circumferential recessed
portion Bf around the peripheral edge Bb of the opening so that the gas barrier layer
Bd having a gas barrier property is exposed at the circumferential recessed portion.
[0120] In the shown embodiment, the gas barrier member 10, which forms the connector A fitted
to the fuel tank B, includes the tubular portion 11 and the flanged portion 12 provided
on the peripheral side of the tubular portion 11 and having a greater side than the
opening Ba of the fuel tank B. The gas barrier member also includes a cylindrical
portion 23 forming the fuel cutoff valve 3 and having a relatively large diameter.
The gas barrier member 10 is made of polybutylene terephthalate, polyphenylene sulfide,
a liquid crystal polymer, aliphatic polyketone, aromatic polyamide, a blended polymer
of an ethylene-vinyl alcohol copolymer and high-density polyethylene, a blended polymer
of polyamide and polyethylene, a blended polymer of polyamide and high-density polyethylene,
or polyethylene terephthalate.
[0121] The tubular portion 11 forming the gas barrier member 10 in the shown embodiment
includes a vertical tubular portion 11b vertically projecting from the flanged portion
12 and a horizontal tubular portion 11a rectangularly connected to the vertical tubular
portion 11b at right angles. The tubular portion also includes a tubular projected
portion 11f, which downwardly projects from the flanged portion 12 and communicates
with the vertical tubular portion 11b. The tubular projected portion 11f has a lower
edge formed with a valve seat 11f' as a recessed portion provided at a lower end of
a passage 11e in the tubular portion.
[0122] The flanged portion 12, which is provided on a peripheral portion of the vertical
tubular portion 11a, is configured to have a greater side than the opening Ba formed
in the fuel tank B. In other words, the flanged portion 12 provided on the tubular
portion 11 is provided so as to extend from the peripheral portion of the tubular
portion 11 toward a lateral portion of the peripheral edge Bb of the opening formed
in the fuel tank B. More specifically, the flanged portion 12 is formed in a circular
plate shape, and the flanged portion 12 is configured to have a greater diameter than
the opening Ba formed in a circular shape.
[0123] The flanged portion 12 thus constructed has an outer peripheral edge on a side facing
the outer surface of the fuel tank B, i.e., on a projecting side of the projected
tubular portion 11f, formed with an annular projected portion 12a', which projects
in a bent shape downwardly, i.e., toward the fuel tank B.
[0124] The gas barrier member 10 thus constructed has a lower side, i.e., the projecting
side of the projected tubular portion 11f, formed integrally with the cylindrical
portion 23 forming the fuel cutoff valve.
[0125] The cylindrical portion 23 forming the fuel cutoff valve 3 is formed an open-bottomed
cylindrical body, which is formed integrally with the flanged portion 12 so as to
project downwardly from the lower side of the flanged portion 12 and to surround the
tubular projected portion 11f. The cylindrical portion has an outer portion on a leading
side as a lower edge formed with an engagement projection 23b for engagement with
a lid 24. The cylindrical portion has a peripheral wall formed with a plurality of
apertures 23a. The cylindrical portion 23 has an inner wall formed with a plurality
of guide ribs 23c, which extend from a lower portion toward the flanged portion 12.
[0126] The apertures 23a formed in the cylindrical portion 23 provides a structure wherein
gas or other fluid can smoothly move between the inner space of the fuel tank B and
the inner space of the cylindrical portion 23, which has the float 40 housed therein
and is closed by the lid 24.
[0127] The outer shell 50 is integrally fitted to the gas barrier member 10 so as to be
continuously fitted to an upper peripheral surface of the cylindrical portion 23 in
the gas barrier member 10, a surface of the flanged portion 12 continuous to the upper
peripheral surface, and an inner surface of the annular projected portion 12a' continuous
to the surface of the flanged portion 12. The connector A can be melt-bonded and fitted
to the fuel tank B by use of the outer shell 50.
[0128] The outer shell 50 in the shown example is integrally provided with a cylindrical
part 53 fitted to the upper peripheral surface of the cylindrical portion 23, a flange
part 52 fitted to a lower side of the flanged portion 12, and a projected part 54
fitted to the inner surface of the annular projected portion 12a' and projecting further
downwardly than the annular projected portion 12a'. When the projected part 54 has
a leading end melt-bonded to the circumferential recessed portion Bf of the fuel tank
B, the annular projected portion 12a' has a leading end gotten in close contact with
the outer surface of the fuel tank B.
[0129] The outer shell 50 forming the connector A may be fitted to the gas barrier member
10 by any one of various types of methods. For example, the outer shell can be integrally
fitted to the gas barrier member 10 by, e.g., inserting the gas barrier member 10
in a mold and injecting a synthetic resin into the mold.
[0130] For example, even if the gas barrier member 10 is made of polybutylene terephthalate
having a superior gas barrier property, the outer shell 50 can be integrally fitted
to the gas barrier member 10 in reliable fashion since the outer shell 50 is typically
formed as the outer shell portion 50c made of a modified polyolefin resin and having
an adhesive property. The connector A with the outer shell portion 50c can be fitted
to the fuel tank B since the outer shell portion can be properly melt-bonded to the
synthetic resin of the fuel tank B, such as polyethylene and high-density polyethylene.
[0131] The outer shell 50 can be also properly melt-bonded to the synthetic resin Bd having
a gas barrier property in the fuel tank B to fit the connector A to the fuel tank
B since the outer shell 50 forming the connector A is formed as the outer shell portion
50c made of a modified polyolefin resin having an adhesive property as explained.
[0132] In the connector A including the outer shell 50 thus constructed and the gas barrier
member 10, the tubular portion 11 in the gas barrier member 10 forms a tubular unit
1 of the connector A, and the outer shell 50 and the gas barrier member 10 form a
flange unit 2 of the connector A laterally projecting from the tubular unit 1. The
flange unit 2 has a projecting edge provided with an annular projected portion 2a',
which projects toward the fuel tank B and is formed from the annular projected portion
12a' and the projected portion 54. In the shown embodiment, the flange portion 2 has
a lower side provided with the typical fuel cutoff valve 3.
[0133] The float 40 forming the fuel cutoff valve 3 is made of, e.g., polyacetal. The float
is housed in the cylindrical portion 23 so as to be guided by the guide ribs 23c and
is vertically movable in smooth fashion, following a change in the fuel liquid level.
The float has the upper end provided with the valve body 40a, which gets in close
contact with the valve seat 11f' to close the passage 11e in upper movement. The float
has a substantially central portion on a lower side formed with the recess 40b extending
upwardly. The recess 40b has the annular recess 40b' extending further upwardly. The
recess 40b also has the circular base 40c formed therein. The float also has the hole
40d formed therein so as to communicate between the recess 40b and the upper end of
the float 40.
[0134] The lid 24, which keeps the float 40 forming the fuel cutoff valve 3 in an incorporated
state in the cylindrical portion 23, includes a cylindrical peripheral wall 24b upwardly
extending from a peripheral edge of a bottom wall 24a formed in a circular plate.
The cylindrical peripheral wall 24b houses the cylindrical portion 23 so as to get
a leading edge of the cylindrical portion 23 in touch with the bottom wall 24a. The
lid is assembled to the cylindrical portion 23 by engaging the engagement projection
23b formed on the cylindrical portion 23 with an edge of an engagement slot 24c formed
in the cylindrical peripheral wall 24b. By a helical compression spring 41 disposed
on a circular base 24d formed at a substantially central portion on an inner side
of the lid 24 and on the circular base 40c of the float 40, the float 40 can float
up so as to be easily movable in the cylindrical portion 23, following a change in
fuel the liquid level.
[0135] The lid 24, which incorporates the float 40 into the cylindrical portion 23, has
the bottom wall 24a formed with a plurality of apertures 24e vertically passing therethrough,
allowing fuel or gas to easily flow into and out of the cylindrical portion 23.
[0136] When the float 40 does not receive the buoyancy from the fuel liquid, the helical
compression spring 41 balances with the weight of the float 40 and elastically supports
the float 40 so as to maintain the valve body 40a in a position away from the valve
seat 11f'. When the float 40 receives the buoyancy from the fuel liquid, the helical
compression spring allows the float 40 to float up easily and move upwardly by the
buoyancy. In the latter case, the helical compression spring causes the float 40 to
press its valve body 40a into contact with the valve seat 11f' against the buoyancy,
e.g., if the vehicle with the fuel tank turns over.
[0137] In the connector A, which includes the tubular unit 1 and the flange unit 2 comprising
the outer shell 50 and the gas barrier member 10 thus constructed and also includes
the fuel cutoff valve 3, the cylindrical portion 23 has the float 40 housed therein
and the lid 24 fitted to the open bottom thereof with the helical compression spring
41 interposed between the housed float 40 and the lid.
[0138] The connector A thus constructed includes the tubular unit 1 with the passage 11e,
the flange unit 2 provided on the peripheral portion of the tubular unit 1 and having
a greater side than the opening Ba, and the fuel cutoff valve 3. With the cylindrical
portion 23 of the fuel cutoff valve 3 inserted into the fuel tank B through the opening
Ba of the fuel tank B, the flange unit 2 is melt-bonded to a surface of the fuel tank,
which is made of a synthetic resin at least around the peripheral edge Bb of the opening.
Thus, the connector A is used for connecting the fuel tank B and a pipe C in communicating
fashion through the passage 11e.
[0139] The opening Ba in the shown embodiment is formed as a circular opening, and the flange
unit 2 is formed in a circular plate shape and has a greater diameter than the opening
Ba.
[0140] The connector A in the shown example includes the tubular portion 1, which specifically
comprises the vertically tubular portion 11b projecting upwardly, the horizontal tubular
portion 11a connected to an upper end of the vertical tubular portion 11b so as to
be bent from the vertical tubular portion 11b at right angles, and the tubular projected
portion 11f forming the valve seat 11f'. The connector also includes the flange unit
2, which is formed in a circular plate shape and laterally extends from a lower peripheral
portion of the vertical tubular portion 11b in the tubular unit 1. Additionally, the
flange unit includes the fuel cutoff valve 3. In other words, the connector includes
the cylindrical portion 23 downwardly projecting from the lower side of the flange
unit 2, the lid 24 fitted by engaging the engagement slot 24c with the engagement
projection 23b formed on a lower edge of the cylindrical portion 23, the tubular projected
portion 11f projecting from the lower side of the flange unit 2 so as to communicate
with the vertical tubular portion 11b and having the lower edge formed with the recessed
valve seat 11f', and the float 40 housed in a float chamber formed by the flange unit
2 having the tubular projected portion 11f with the valve seat 11f', the cylindrical
portion 23 and the lid 24 so as to be vertically movable in response to a change in
the liquid level of a liquid entering the float chamber. The float 40 has the upper
side formed with the valve body 40a, which gets in contact with the valve seat 11f'
in the tubular projected portion 11f to close the passage 11e in the tubular portion
1, following upward movement of the float 40 caused by a change in the fuel liquid
level.
[0141] The connector A thus constructed has the side of the cylindrical portion 23 inserted
into the fuel tank B through the opening Ba formed in the upper side of the fuel tank
B. While the annular projected portion 12a' of the gas barrier member 10 in the annular
projected portion 2a' is caused to abut against the outer surface of the fuel tank
B, the projected portion 54, which comprises the outer shell 50 in the annular projected
portion 2a' to be housed in the circumferential recessed portion Bf formed in the
fuel tank B, has a leading edge melt-bonded to the surface of the circumferential
recessed portion Bf to fit the connector to the fuel tank B.
[0142] By fitting the connector A to the inner area Bc of the opening formed in the fuel
tank B as explained, the gas barrier member 10 can effectively decrease the leakage
of evaporative emissions deriving from the fuel from the fuel tank B since the annular
projected portion 12a' formed by the gas barrier member 10 is gotten in close contact
with the surface of the fuel tank B.
[0143] The gas barrier member 10 may be made of a synthetic resin having a superior gas
barrier property, such as polybutylene terephthalate, since the outer shell 50 is
made of a modified polyolefin resin having an adhesive property.
[0144] The connector A, which has been fitted to the fuel tank B as explained, may be used
for connection with a suitable pipe C.
[0145] In order to that the connector A can easily and reliably maintain the connection
with the pipe C, the tubular unit 1 of the connector has an outer peripheral surface
of the horizontal tubular portion 11a formed with a plurality of ridges, which comprise
conical guides 1c having a diameter gradually reduced toward the open end of the tubular
unit and vertical stepped surfaces 1d extending from respective edges of the conical
guides remote from the open end to the outer peripheral surface of the horizontal
tubular portion 11a, in the shown embodiment.
(4) Fuel tank connector A according to the fourth embodiment
[0146] Next, the fuel tank connector A according to the fourth embodiment shown in Figs.
10-18 will be specifically described.
[0147] The fuel tank connector A in the shown embodiment is configured as an instrument
to connect any type of pipe C to a fuel tank B, and is in particular a fuel tank connector
A with the typical fuel cutoff valve 3.
[0148] The fuel tank connector A in the shown embodiment is a connector A adapted to be
fitted to an inner area Bc of an opening Ba so as to cover, from outside, the opening
Ba formed in the fuel tank B to connect the fuel tank B and a pipe C in communicating
fashion. The connector A includes the gas barrier member 10, which comprises the tubular
portion 11 and the flanged portion 12 provided on a peripheral side of the tubular
portion 11 and having a greater side than the opening Ba of the fuel tank B, and which
is made of a synthetic resin having a gas barrier property. The gas barrier member
10 is made of polybutylene terephthalate, polyphenylene sulfide, a liquid crystal
polymer, aliphatic polyketone, aromatic polyamide, a blended polymer of an ethylene-vinyl
alcohol copolymer and high-density polyethylene, a blended polymer of polyamide and
polyethylene, a blended polymer of polyamide and high-density polyethylene, or polyethylene
terephthalate. In the shown embodiment, the gas barrier member 10 has at least a portion
of a surface covered with the outer shell 50, more specifically, at least a portion
of a surface covered with an outer shell portion 50d made of polyethylene or high-density
polyethylene. The connector A can effectively minimize that evaporative emissions
deriving from the fuel in the fuel tank B leak from the connector.
[0149] The fuel tank connector A in the shown embodiment is used as an instrument to connect
any type of pipe C to the fuel tank B. In the shown embodiment, the connector A is
provided with the typical fuel cutoff valve 3 and is fitted to the upper side of the
fuel tank B as a typical example. The connector serves to feed, e.g., evaporative
emissions deriving from fuel to a charcoal canister or another device and to prevent
the fuel from flowing out when the fuel level in the fuel tank B changes.
[0150] In the fuel tank B, to which the connector A in the shown embodiment is fitted, at
least a portion of the tank with the outer shell 50 of the connector A melt-bonded
thereto, i.e., an outer surface of the tank around a peripheral edge Bb of the opening
in the fuel tank B is made of a synthetic resin capable of being melt-bonded to the
outer shell 50 and includes a gas barrier layer, i.e., a layer difficult to pass evaporative
emissions from the fuel.
[0151] The fuel tank B typically includes an outer surface layer Be made of a synthetic
resin convenient for melt-bonding with the connector A, such as high-density polyethylene,
and the gas barrier layer Bd made of a synthetic resin layer to make it difficult
to pass evaporative emissions from the fuel.
[0152] The connector A in the shown embodiment includes the tubular unit 1 with a bore 1e,
the flange unit 2 provided on a peripheral portion of the tubular unit 1 and having
a greater side than the opening Ba, and the fuel cutoff valve 3. With the cylindrical
portion 23 of the fuel cutoff valve 3 inserted into the fuel tank B through the opening
Ba of the fuel tank B, the flange unit 2 has a leading end melt-bonded to a surface
of the fuel tank, which is made of a synthetic resin at least around the peripheral
edge Bb of the opening. Thus, the connector A is used for connecting the fuel tank
B and a pipe C in communicating fashion through the bore 1e.
[0153] The opening Ba in the shown embodiment is formed as a circular opening, and the flange
unit 2 is formed in a circular plate shape and has a greater diameter than the opening
Ba.
[0154] More specifically, the connector A in the shown embodiment includes the tubular unit
1, which comprises a vertical tubular portion 1a projecting upwardly and a horizontal
tubular portion 1b connected to an upper end of the vertical tubular portion 1a so
as to be bent from the vertical tubular portion 1a at right angles. The connector
also includes the flange unit 2, which is formed in a circular plate shape and projects
laterally from a lower outer peripheral portion of the vertical tubular portion 1a
in the tubular unit 1. The flange unit is provided with the fuel cutoff valve 3, which
comprises the disk-shaped portion 21 jutted downwardly from the flange unit 2 on a
lower side of the flange unit 2, i.e., on a side of the flange unit opposite to the
tubular unit 1, the cylindrical portion 23 projecting downwardly from a peripheral
edge of the disk-shaped portion 21, the lid 24 having the engagement slot 24c engaged
with the engagement projection 23b formed on a lower end of the cylindrical portion
23 to be fitted to the cylindrical portion, and the valve seat unit 30 provided in
the recessed portion 22 of the disk-shaped portion 21 so as to communicate with the
bore 1e in the tubular unit 1. The fuel cutoff valve also comprises the float chamber
formed by the disk-shaped portion 21 having the valve seat unit 30 with a valve seat
30b, the cylindrical portion 23 and the lid 24, and the float 40 housed in the float
chamber so as to be vertically movable in response to a change in the liquid level
of a liquid entering into the float chamber. The float 40 has the upper side formed
with the valve body 40a, which gets in close contact with the valve seat 30b in the
valve seat unit 30 to close the bore 1e in the tubular unit 1 when the float 40 moves
toward the valve seat 30b, following a change in the fuel liquid level.
[0155] The gas barrier member 10 provided on the connector A is made of a synthetic resin
having a gas barrier property to avoid the transmission of gas, typically evaporative
emissions deriving from the fuel in the tank B, as much as possible. Examples of the
synthetic resin are polybutylene terephthalate, polyphenylene sulfide, a liquid crystal
polymer, aliphatic polyketone, aromatic polyamide, a blended polymer of an ethylene-vinyl
alcohol copolymer and high-density polyethylene, a blended polymer of polyamide and
polyethylene, a blended polymer of polyamide and high-density polyethylene, and polyethylene
terephthalate. In the shown embodiment, the gas barrier member includes the tubular
portion 11 with a passage 11e forming the bore 1e and the flange portion 12 projecting
laterally from the peripheral edge of the one end of the tubular portion 11.
[0156] The tubular unit 11 includes a vertical tubular portion 11b and a horizontal tubular
portion 11a connected to the vertical tubular portion 11b at right angles, which provide
an elbow-like shape. The tubular portion 11 is integrally formed with the flanged
portion 12, which projects laterally from the lower outer peripheral portion of the
vertical tubular portion 11b.
[0157] The flanged portion 12, which is provided on the outer peripheral portion of the
vertical tubular portion 11b, has a greater side than the opening Ba in the fuel tank
B. In other words, the flanged portion 12, which is provided on the tubular portion
11, extends from the outer peripheral portion of the tubular portion 11 toward a lateral
side of the peripheral edge Bb of the opening in the fuel tank B. Specifically, the
flanged portion 12 is formed in a circular plate-like shape, and the flanged portion
12 has a greater diameter than the opening Ba, which is formed in a circular shape.
[0158] The flanged portion 12 thus constructed has an annular projected portion 12a projected
from an outer peripheral edge thereof on a side thereon facing the fuel tank B, i.e.,
a side thereof opposite to the projected tubular portion 11 so as to extend in a bent
shape downwardly, i.e., toward the fuel tank B.
[0159] The gas barrier member 10 thus constructed has a lower side, i.e., a side opposite
to the projected tubular portion 11, fitted integrally with the fuel cutoff valve
3.
[0160] The fuel cutoff valve 3 includes the cylindrical body 20 having the upper end integrally
provided with the disk-shaped portion 21 so as to be integral with the gas barrier
member 10, the valve seat unit 30 integrally fitted in the disk-shaped portion 21
of the cylindrical body 20, and the lid 24 fitted to the lower end of the open-bottomed
cylindrical portion 23 in the cylindrical body 20. The fuel cutoff valve also includes
the float 40, which is housed in the float chamber provided in the cylindrical body
closed by the lid 24, and which opens and closes the valve seat 30b in the valve unit
30, following a change in the fuel liquid level.
[0161] The cylindrical body 20 forming the fuel cutoff valve 3 includes the disk-shaped
portion 21 and the cylindrical portion 23 integrally provided on the disk-shaped portion
21 so as to project therefrom. The cylindrical body may be made of any type of synthetic
resin, typically a synthetic resin having a gas barrier property, such as polyacetal.
[0162] The disk-shaped portion 21 forming the cylindrical unit 20 has the cavity 21a formed
therein so as to communicate with outside and accept a molding resin. The disk-shaped
portion has the cylindrical portion 23 integrally provided thereon to extend downwardly
from the outer peripheral edge thereof. The disk-shaped portion 21 has a substantially
central portion formed with the recessed portion 22, which communicate with the passage
11e in the tubular portion 11 and form the opening 11c of the tubular portion 11.
[0163] The recessed portion 22 formed in the disk-shaped portion 21 communicates with the
passage 11e in the tubular portion 11 and has a greater diameter than the passage
11e. In the shown embodiment, the recessed portion comprises the larger diameter of
stepped hole 22a formed in a lower portion of the disk-shaped portion 21 so as to
extend upwardly, the conical hole 22b extending from the upper end of the larger diameter
of stepped hole 22a toward the tubular portion 11, and the additional stepped hole
22c extending from the conical hole 22b to the tubular portion 11.
[0164] The cylindrical portion 23 is formed as an open-bottomed cylindrical member, which
projects from the disk-shaped portion 21 as being integral therewith. The cylindrical
portion has the outer portion on the leading edge as the lower edge formed with the
engagement projection 23b for engagement with the lid 24. The cylindrical portion
has the outer peripheral wall formed with the plural apertures 23a and the inner wall
formed with the plural guide ribs 23c so as to extend from a lower portion of the
inner wall of the cylindrical portion toward the disk-shaped portion 21.
[0165] The apertures 23a formed in the cylindrical portion 23 provide a structure wherein
fluid, such as gas, can smoothly move between the inner space of the fuel tank B and
the inner space in the cylindrical portion 23, which houses the float 40 therein and
is closed by the lid 24.
[0166] The cylindrical body 20 thus constructed and the gas barrier member 10 are integrally
fitted by, e.g., inserting the cylindrical body 20 in a mold, injecting a synthetic
resin for molding the gas barrier member 10 into the mold by injection or anther way,
and molding the gas barrier member 10 so as to cover a peripheral portion of the disk-shaped
portion 21 in the cylindrical body 20 and a side of the disk-shaped portion 21 remote
from the projected cylindrical portion 23 with the synthetic resin as well as filling
the synthetic resin into the cavity 21a in the cylindrical body 21.
[0167] In the shown embodiment, the gas barrier member 10 is integrally fitted to the cylindrical
body 20 so as to include the flanged portion 12 covering a side of the disk-shaped
portion 21 opposite to the cylindrical portion 23 and projecting laterally from the
side, the covering portion 12b projecting from a lower side of the flanged portion
12 so as to cover a circumferential surface of the disk-shaped portion 21, the tubular
portion 11 projecting upwardly from an upper side of the flanged portion 12 so as
to have the passage 11e in communication with the additional stepped hole 22c in the
disk-shaped portion 21, and the annular projected portion 12a extending downwardly
from a leading edge of the flanged portion 12 so as to have a bent shape.
[0168] The gas barrier member 10, which is integrally fitted to the cylindrical body, has
an outer surface thereof, i.e., an outer surface thereof from the outer surface of
the annular projected portion 12a to the open end 11d of the tubular portion 11 in
the shown embodiment, covered by the outer shell 50, which made of polyethylene or
high-density polyethylene.
[0169] The outer shell 50 to be provided on the gas barrier member 10 can be formed on the
surface of the gas barrier member 10 by plastics molding, wherein the cylindrical
body 20 with the gas barrier member 10 integrally fitted thereto is inserted into
a mold, for instance.
[0170] In the shown embodiment, the flange unit 2 and the tubular unit 1 of the connector
A is formed so that the outer shell 50 is integrally fitted to the flanged portion
12 and the tubular portion 11 in the gas barrier member 10. The flange unit 2 has
a leading edge provided with an annular projected portion 51, which is formed by the
annular projected portion 12a and the outer shell 50 covering the annular projected
portion 12a.
[0171] When the gas barrier member 10 of the connector A is made of a blended polymer of
polyamide and polyethylene or a blended polymer of polyamide and high-density polyethylene,
the integration between the gas barrier member 10 and the outer shell 50 made of polyethylene
or high-density polyethylene becomes better. In this case, the connector can be conveniently
melt-bonded to the fuel tank B as well.
[0172] The valve seat unit, which is provided in the recessed portion 22 of the disk-shaped
portion 21 in the cylindrical unit 20 and provides the valve seat 30b of the fuel
cutoff valve 3, is made of a synthetic resin providing a gas barrier function to the
connector A together with the disk-shaped portion 21, i.e., any type of synthetic
resin having a gas barrier property capable of effectively avoiding the transmission
of evaporative emissions from the fuel, such as polyacetal. The valve seat unit has
such a structure wherein the valve seat 30b, which receives the valve body 40a of
the float 40 to be closed, is provided on the edge of the aperture 30a vertically
passing through the valve seat unit. The valve seat unit can be incorporated in the
recessed portion 22.
[0173] In other words, the valve seat unit 30 has the aperture 30a formed in a substantially
central portion so as to vertically pass therethrough in communication with the bore
1e (11e). The aperture 30a comprises the smaller diameter of orifice 30a' at a central
portion, the conical valve seat 30b extending downwardly from the smaller diameter
of aperture 30a' and having a diameter gradually increased toward the lower edge of
the aperture 30a, and the annular groove 30c provided on the upper side of the valve
seat unit 30 so as to surround the aperture 30a. The annular groove 30c provides the
cylindrical part 30d on a central portion of the upper side of the valve seat unit
30. The outer wall of the annular groove 30c forming the cylindrical part 30b forms
the upper disk-like part 30e. The valve seat unit has a lower side than the upper
disk-like portion 30e formed as a lower disk-like portion 30f having a greater diameter
than the upper disk-like portion 30e. The valve seat unit 30 is melt-bonded and integrally
fitted to the disk-shaped portion 21, housing the lower disk-like portion 30f in the
larger diameter stepped hole 22a at the lowest position so that the upper disk-like
portion 30e has the upper end pressed against the conical hole 22b, and the lower
disk-like portion 30f has the upper end gotten in close contact with the upper end
of the larger diameter of stepped hole 22a.
[0174] The float 40, which is incorporated into the cylindrical body 20 thus constructed,
made of, e.g., polyacetal. The float is housed in the cylindrical portion 23 so as
to be guided by the guide ribs to be vertically movable in smooth fashion, following
a change in the fuel liquid level. The float has the upper side provided with the
valve body 40a, which gets in contact with the valve seat 30b to close the aperture
30a of the valve seat unit 30 in upward movement toward the valve seat 30b, following
a change in the fuel liquid level. The float has a substantially central portion on
the lower side formed with the recess 40b upwardly extending. The float has the annular
recess 40b' provided in the recess 40b so as to extend further upwardly. The float
also has the circular base 40c formed in the recess 40b. The float has the hole 40d
communicating between the recess 40b and the upper end surface of the float 40.
The lid 24, which keeps the float 40 forming the fuel cutoff valve 3 in an incorporated
state in the cylindrical portion 23, includes the cylindrical peripheral wall 24b,
which extends upwardly from the peripheral edge of the bottom wall 24a in a circular
plate shape. The lid receives the cylindrical portion 23 in the cylindrical peripheral
wall 24b so as to get the leading edge of the cylindrical portion 23 in touch with
the bottom wall 24a. The lid is fitted to the cylindrical portion 23 by engaging the
engagement projection 23b provided on the cylindrical portion 23 with an edge of the
engagement slot 24c formed in the cylindrical peripheral wall 24b. By the helical
compression spring 41, which is disposed on the circular base 24d provided on the
substantially central portion on the inner side of the lid 24 and on the circular
base 40c on the float 40, the float 40 can easily float up and move in the cylindrical
portion 23, following a change in the fuel liquid level.
[0175] The lid 24, which incorporates the float 40 into the cylindrical portion 23, has
the bottom wall 24a formed with the plural apertures 24e vertically passing therethrough,
allowing fuel or gas to easily flow in and out of the cylindrical portion 23.
[0176] When the float 40 does not receive the buoyancy from the fuel liquid, the helical
compression spring 41 balances with the weight of the float 40 and elastically supports
the float 40 so as to maintain the valve body 40a in a position away from the valve
seat 30b. When the float 40 receives the buoyancy from the fuel liquid, the helical
compression spring allows the float 40 to float up easily and move upwardly by the
buoyancy. In the latter case, the helical compression spring causes the float 40 to
press its valve body 40a into contact with the valve seat 30b against the buoyancy,
e.g., if the vehicle with the fuel tank turns over.
[0177] In the connector A, which includes the tubular unit 1 and the flange unit 2 comprising
the outer shell 50 and the gas barrier member 10 thus constructed and also includes
the fuel cutoff valve 3, the valve seat unit 30 is integrally melt-bonded and fitted
to the disk-shaped portion 21 forming the fuel cutoff valve 3. The cylindrical portion
23 has the float 40 housed therein and the lid 24 fitted to the open bottom thereof
with the helical compression spring 41 interposed between the housed float 40 and
the lid.
[0178] In the shown embodiment, the connector A thus constructed has the side of the cylindrical
portion 23 inserted into the fuel tank B through the opening Ba formed in the upper
side of the fuel tank B. The annular projected portion 12a of the gas barrier member
10 and the annular projected portion 51 in the connector A are melt-bonded to the
fuel tank B.
[0179] By fitting the connector A to the inner area Bc of the opening formed in the fuel
tank B as explained, the gas barrier member 10 can effectively decrease the leakage
of evaporative emissions deriving from the fuel from the fuel tank B.
[0180] The connector A can be easily and reliably fitted to the fuel tank B since fitting
the connector A to the fuel tank B is carried out by melt-bonding the connector A
to the fuel tank B.
[0181] In this embodiment, the annular projected portion 51, which is provided on the outer
shell 50 made of polyethylene or high-density polyethylene and projects toward the
outer surface of the fuel tank B so as to cover the leading edge of the flanged portion
12 of the gas barrier member 10, is melt-bonded to the fuel tank. While the gas barrier
member 10 can effectively decrease the leakage of evaporative emissions from the fuel
tank B, the connector A can be fitted to, with high melt-bonding strength ensured,
to the fuel tank B, which has the outer surface layer Be made of polyethylene or high-density
polyethylene.
[0182] In this embodiment, the outer shell 50 made of polyethylene or high-density polyethylene
is formed on the gas barrier member 10 in such a state that a projection 52, which
is provided on one of the annular projected portion 51 of the outer shell 50 made
of polyethylene or high-density polyethylene and the leading end of the flanged portion
12 of the gas barrier member 10, bites into the other one of the annular projected
portion 51 and the leading portion of the flanged portion 12.
[0183] In this embodiment, specifically, the annular projected portion 12a, which is formed
on the leading edge of the flanged portion 12 of the gas barrier member 10, has an
outer side formed with an annular groove 12c, and the annular projected portion 51
of the outer shell 50 has an inner side formed with an annular projection 52' bitten
into the annular groove 12c. In other words, in this embodiment, a molding process,
wherein the annular groove 12c is formed in the outer side of the annular projected
portion 12a of the gas barrier member 10, is carried out to obtain a partly molded
product with the gas barrier member 10 thus molded, and then, the partly molded product
is used as an insert to mold the outer shell 50, forming the annular projection 52'
on the inner side of the annular projected portion 51 of the outer shell 50 so as
to be bitten in the annular groove 12c.
[0184] Thus, the integration between the annular projected portion 12a formed on the leading
edge of the flanged portion 12 in the gas barrier member 10 and the annular projected
portion 51 of the outer shell 50 can be ensured with high level in this embodiment.
In particular, when both of the annular projected portions 12a and 51 are heated and
melted by a heating plate for melt-bonding, both of the annular projected portions
12a and 51 can be melt-bonded to the fuel tank B, being adequately melted in a planned
range.
[0185] The projection 52 may be formed on the outer side of the annular projected portion
12a of the gas barrier member 10. In this case, the outer shell 50 is formed so as
to have the projection 52 bitten therein.
[0186] The projection 52 may comprise a plurality of projections, which are provided in
discontinuous fashion so as to be located along the inner area Bc of the opening formed
in the fuel tank B.
[0187] In this embodiment, the annular projected portion 12a formed on the leading edge
of the flanged portion 12 in the gas barrier member 10, and the annular projected
portion 51 of the outer shell 50 made of polyethylene or high-density polyethylene
project downwardly by substantially the same length. In other words, both of the annular
projected portion 12a and 51 have projected surfaces 12d and 53 facing the outer surface
of the fuel tank B positioned substantially flush with each other.
[0188] The annular projected portion 12a of the gas barrier member 10 and the annular projected
portion 51 of the outer shell 50 made of polyethylene or high-density polyethylene
have a space 60 formed therebetween so as to open toward the outer surface of the
fuel tank B.
[0189] Specifically, in this embodiment, the annular projected portion 12a of the gas barrier
member 10 is formed so that an outer surface of the annular projected portion 12a
between the annular groove 12c formed in the outer side of the annular projected portion
12a and the projected surface 12d of the annular projected portion 12a forms a slant
surface toward the peripheral edge Bb of the opening of the fuel tank B so as to have
a size gradually enlarged toward the projected surface 12d. The annular projected
portion 51 of the outer shell 50 has an inner surface facing the slant surface extending
substantially perpendicular to the outer surface of the fuel tank B, thus providing
the space 60 in an annular shape between the slant surface and the inner surface.
[0190] In this embodiment, when the annular projected portion 51 of the outer shell 50 is
heated and melted, the melted material of polyethylene or high-density polyethylene
forming the annular projected portion 50 can come into the space 60. As a result,
the melt-bonding strength with respect to the fuel tank B having the outer surface
layer Be made of, in particular, high-density polyethylene can be further improved
since the annular projected portion 50 can be melt-bonded to the fuel tank B, spreading
the melted material of polyethylene or high-density polyethylene in a wide range.
[0191] Unlike in the example shown in Figs. 10-16, the annular projected portion 12a provided
on the flanged portion 12 in the gas barrier member 10 may project so as to have a
smaller projecting length than the annular projected portion 51 of the outer shell
50 made of polyethylene or high-density polyethylene (Fig. 17).
[0192] In other words, the projected surface 12d of the annular projected portion 12a in
the gas barrier member 10 is lower (i.e., lower in a direction away from the outer
surface of the fuel tank B) than the projected surface 53 of the annular projected
portion 51 in the outer shell 50, which faces the outer surface of the fuel tank B
as shown in Fig. 17.
[0193] In this case, when the annular projected portion 51 in the outer shell 50 is heated
and melted, the melted material forming the annular projected portion 51 and made
of polyethylene or high-density polyethylene can come into between the projected surface
12d of the annular projected portion 12a in the gas barrier member 10 and the outer
surface of the fuel tank B. The melt-bonding strength with respect to the fuel tank
B having the outer surface layer Be made of, in particular, high-density polyethylene
can be further improved since the annular projected portion 51 can be melt-bonded
to the fuel tank B, spreading the melted material of polyethylene or high-density
polyethylene in a wide range in this case as well.
[0194] Unlike in the example shown in Figs. 10-16, the melt-bonding may be carried out so
as to leave some part of the space 60 unfilled even after the annular projected portion
51 in the outer shell 50 has been melt-bonded to the fuel tank B (Fig. 19 and Fig.
20).
[0195] In the example shown in Fig. 20, both of the annular projected portion 51 in the
outer shell 50 and the annular projected portion 12a in the gas barrier member 10
are melt-bonded to the outer surface layer Be of the fuel tank B made of high-density
polyethylene, and the space 60 is formed so as to have an enough size to prevent the
space 60 from being fully filled by the melt-bonding.
[0196] In this case, even if the gas barrier member 10 is swollen by fuel or evaporative
emissions from the fuel, the unfilled part of the space 60 can absorb the swell to
make it difficult that the melt-bonded portion between the annular projected portion
51 in the outer shell 50 and the fuel tank B has a force reducing the melt-bonding
strength applied thereto.
[0197] Unlike in the example shown in Figs. 10-16, the upper side of the gas barrier member
10, which is covered by the outer shell 50 made of polyethylene or high-density polyethylene,
may be stepped to have a stepped surface 70 facing the leading edge of the flanged
portion 12 in the gas barrier member 10 (Fig. 21 and Fig. 22).
[0198] In the example shown in Fig. 22, both of the annular projected portion 51 in the
outer shell 50 and the annular projected portion 12 in the gas barrier member 10 are
melt-bonded to the outer surface layer Be of the fuel tank B made of high-density
polyethylene, and the upper side of the gas barrier member 10 thus melt-bonded is
stepped so as to have the stepped surface 70 facing the leading edge of the flanged
portion 12 in the gas barrier member 10. The outer shell 50 has an opposed inner surface
71 formed accordingly so as to be in contact with the stepped surface 70.
[0199] Even if the gas barrier member 10 is swollen by the fuel or evaporation emissions
from the fuel in the fuel tank connector thus constructed, the opposed inner surface
71 of the outer shell 50 made of polyethylene or high-density polyethylene in contact
with the stepped surface 70 can receive the force caused by the swell to disperse
the force, making it difficult that the melt-bonded portion between the annular projected
portion 51 in the outer shell 50 and the fuel tank B has a force reducing the melt-bonding
strength applied thereto.
[0200] The connector A, which has been fitted to the fuel tank B as explained, may be used
for connection with a suitable pipe C.
[0201] In order to that the connector A can easily and reliably maintain the connection
with the pipe C, the tubular unit 1 of the connector has the outer peripheral surface
of the horizontal tubular portion 1b formed with the plural ridges, which comprise
the conical guides 1c having a diameter gradually reduced toward the leading edge
and the vertical stepped surfaces 1d extending from respective edges of the conical
guides remote from the leading edge to the outer peripheral surface of the horizontal
tubular portion 1b, in the shown embodiment.
[0202] Obviously, numerous modifications and variations of the present invention are possible
in light of the above teachings. It is therefore to be understood that within the
scope of the appended claims, the invention may be practiced otherwise than as specifically
described herein.